<?php
/**
 * CakePHP :  Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.View.Helper
 * @since         CakePHP(tm) v 2.0
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('AppHelper', 'View/Helper');

/**
 * JsEngineBaseClass
 *
 * Abstract Base Class for All JsEngines to extend. Provides generic methods.
 *
 * @package       Cake.View.Helper
 */
abstract class JsBaseEngineHelper extends AppHelper
{

    /**
     * The js snippet for the current selection.
     *
     * @var string
     */
    public $selection;

    /**
     * Collection of option maps. Option maps allow other helpers to use generic names for engine
     * callbacks and options. Allowing uniform code access for all engine types. Their use is optional
     * for end user use though.
     *
     * @var array
     */
    protected $_optionMap = array();

    /**
     * An array of lowercase method names in the Engine that are buffered unless otherwise disabled.
     * This allows specific 'end point' methods to be automatically buffered by the JsHelper.
     *
     * @var array
     */
    public $bufferedMethods = array('event', 'sortable', 'drag', 'drop', 'slider');

    /**
     * Contains a list of callback names -> default arguments.
     *
     * @var array
     */
    protected $_callbackArguments = array();

    /**
     * Create an `alert()` message in Javascript
     *
     * @param string $message Message you want to alter.
     * @return string completed alert()
     */
    public function alert($message)
    {
        return 'alert("' . $this->escape($message) . '");';
    }

    /**
     * Redirects to a URL. Creates a window.location modification snippet
     * that can be used to trigger 'redirects' from Javascript.
     *
     * @param string|array $url URL
     * @return string completed redirect in javascript
     */
    public function redirect($url = null)
    {
        return 'window.location = "' . Router::url($url) . '";';
    }

    /**
     * Create a `confirm()` message
     *
     * @param string $message Message you want confirmed.
     * @return string completed confirm()
     */
    public function confirm($message)
    {
        return 'confirm("' . $this->escape($message) . '");';
    }

    /**
     * Generate a confirm snippet that returns false from the current
     * function scope.
     *
     * @param string $message Message to use in the confirm dialog.
     * @return string completed confirm with return script
     */
    public function confirmReturn($message)
    {
        $out = 'var _confirm = ' . $this->confirm($message);
        $out .= "if (!_confirm) {\n\treturn false;\n}";
        return $out;
    }

    /**
     * Create a `prompt()` Javascript function
     *
     * @param string $message Message you want to prompt.
     * @param string $default Default message
     * @return string completed prompt()
     */
    public function prompt($message, $default = '')
    {
        return 'prompt("' . $this->escape($message) . '", "' . $this->escape($default) . '");';
    }

    /**
     * Generates a JavaScript object in JavaScript Object Notation (JSON)
     * from an array. Will use native JSON encode method if available, and $useNative == true
     *
     * ### Options:
     *
     * - `prefix` - String prepended to the returned data.
     * - `postfix` - String appended to the returned data.
     *
     * @param array $data Data to be converted.
     * @param array $options Set of options, see above.
     * @return string A JSON code block
     */
    public function object($data = array(), $options = array())
    {
        $defaultOptions = array(
            'prefix' => '', 'postfix' => '',
        );
        $options = array_merge($defaultOptions, $options);

        return $options['prefix'] . json_encode($data) . $options['postfix'];
    }

    /**
     * Converts a PHP-native variable of any type to a JSON-equivalent representation
     *
     * @param mixed $val A PHP variable to be converted to JSON
     * @param boolean $quoteString If false, leaves string values unquoted
     * @return string a JavaScript-safe/JSON representation of $val
     */
    public function value($val = array(), $quoteString = null, $key = 'value')
    {
        if ($quoteString === null) {
            $quoteString = true;
        }
        switch (true) {
            case (is_array($val) || is_object($val)):
                $val = $this->object($val);
                break;
            case ($val === null):
                $val = 'null';
                break;
            case (is_bool($val)):
                $val = ($val === true) ? 'true' : 'false';
                break;
            case (is_int($val)):
                $val = $val;
                break;
            case (is_float($val)):
                $val = sprintf("%.11f", $val);
                break;
            default:
                $val = $this->escape($val);
                if ($quoteString) {
                    $val = '"' . $val . '"';
                }
                break;
        }
        return $val;
    }

    /**
     * Escape a string to be JSON friendly.
     *
     * List of escaped elements:
     *
     * - "\r" => '\n'
     * - "\n" => '\n'
     * - '"' => '\"'
     *
     * @param string $string String that needs to get escaped.
     * @return string Escaped string.
     */
    public function escape($string)
    {
        return $this->_utf8ToHex($string);
    }

    /**
     * Encode a string into JSON. Converts and escapes necessary characters.
     *
     * @param string $string The string that needs to be utf8->hex encoded
     * @return void
     */
    protected function _utf8ToHex($string)
    {
        $length = strlen($string);
        $return = '';
        for ($i = 0; $i < $length; ++$i) {
            $ord = ord($string{$i});
            switch (true) {
                case $ord == 0x08:
                    $return .= '\b';
                    break;
                case $ord == 0x09:
                    $return .= '\t';
                    break;
                case $ord == 0x0A:
                    $return .= '\n';
                    break;
                case $ord == 0x0C:
                    $return .= '\f';
                    break;
                case $ord == 0x0D:
                    $return .= '\r';
                    break;
                case $ord == 0x22:
                case $ord == 0x2F:
                case $ord == 0x5C:
                    $return .= '\\' . $string{$i};
                    break;
                case (($ord >= 0x20) && ($ord <= 0x7F)):
                    $return .= $string{$i};
                    break;
                case (($ord & 0xE0) == 0xC0):
                    if ($i + 1 >= $length) {
                        $i += 1;
                        $return .= '?';
                        break;
                    }
                    $charbits = $string{$i} . $string{$i + 1};
                    $char = Multibyte::utf8($charbits);
                    $return .= sprintf('\u%04s', dechex($char[0]));
                    $i += 1;
                    break;
                case (($ord & 0xF0) == 0xE0):
                    if ($i + 2 >= $length) {
                        $i += 2;
                        $return .= '?';
                        break;
                    }
                    $charbits = $string{$i} . $string{$i + 1} . $string{$i + 2};
                    $char = Multibyte::utf8($charbits);
                    $return .= sprintf('\u%04s', dechex($char[0]));
                    $i += 2;
                    break;
                case (($ord & 0xF8) == 0xF0):
                    if ($i + 3 >= $length) {
                        $i += 3;
                        $return .= '?';
                        break;
                    }
                    $charbits = $string{$i} . $string{$i + 1} . $string{$i + 2} . $string{$i + 3};
                    $char = Multibyte::utf8($charbits);
                    $return .= sprintf('\u%04s', dechex($char[0]));
                    $i += 3;
                    break;
                case (($ord & 0xFC) == 0xF8):
                    if ($i + 4 >= $length) {
                        $i += 4;
                        $return .= '?';
                        break;
                    }
                    $charbits = $string{$i} . $string{$i + 1} . $string{$i + 2} . $string{$i + 3} . $string{$i + 4};
                    $char = Multibyte::utf8($charbits);
                    $return .= sprintf('\u%04s', dechex($char[0]));
                    $i += 4;
                    break;
                case (($ord & 0xFE) == 0xFC):
                    if ($i + 5 >= $length) {
                        $i += 5;
                        $return .= '?';
                        break;
                    }
                    $charbits = $string{$i} . $string{$i + 1} . $string{$i + 2} . $string{$i + 3} . $string{$i + 4} . $string{$i + 5};
                    $char = Multibyte::utf8($charbits);
                    $return .= sprintf('\u%04s', dechex($char[0]));
                    $i += 5;
                    break;
            }
        }
        return $return;
    }

    /**
     * Create javascript selector for a CSS rule
     *
     * @param string $selector The selector that is targeted
     * @return JsBaseEngineHelper instance of $this. Allows chained methods.
     */
    abstract public function get($selector);

    /**
     * Add an event to the script cache. Operates on the currently selected elements.
     *
     * ### Options
     *
     * - `wrap` - Whether you want the callback wrapped in an anonymous function. (defaults to true)
     * - `stop` - Whether you want the event to stopped. (defaults to true)
     *
     * @param string $type Type of event to bind to the current dom id
     * @param string $callback The Javascript function you wish to trigger or the function literal
     * @param array $options Options for the event.
     * @return string completed event handler
     */
    abstract public function event($type, $callback, $options = array());

    /**
     * Create a domReady event. This is a special event in many libraries
     *
     * @param string $functionBody The code to run on domReady
     * @return string completed domReady method
     */
    abstract public function domReady($functionBody);

    /**
     * Create an iteration over the current selection result.
     *
     * @param string $callback The function body you wish to apply during the iteration.
     * @return string completed iteration
     */
    abstract public function each($callback);

    /**
     * Trigger an Effect.
     *
     * ### Supported Effects
     *
     * The following effects are supported by all core JsEngines
     *
     * - `show` - reveal an element.
     * - `hide` - hide an element.
     * - `fadeIn` - Fade in an element.
     * - `fadeOut` - Fade out an element.
     * - `slideIn` - Slide an element in.
     * - `slideOut` - Slide an element out.
     *
     * ### Options
     *
     * - `speed` - Speed at which the animation should occur. Accepted values are 'slow', 'fast'. Not all effects use
     *   the speed option.
     *
     * @param string $name The name of the effect to trigger.
     * @param array $options Array of options for the effect.
     * @return string completed string with effect.
     */
    abstract public function effect($name, $options = array());

    /**
     * Make an XHR request
     *
     * ### Event Options
     *
     * - `complete` - Callback to fire on complete.
     * - `success` - Callback to fire on success.
     * - `before` - Callback to fire on request initialization.
     * - `error` - Callback to fire on request failure.
     *
     * ### Options
     *
     * - `method` - The method to make the request with defaults to GET in more libraries
     * - `async` - Whether or not you want an asynchronous request.
     * - `data` - Additional data to send.
     * - `update` - Dom id to update with the content of the request.
     * - `type` - Data type for response. 'json' and 'html' are supported. Default is html for most libraries.
     * - `evalScripts` - Whether or not <script> tags should be eval'ed.
     * - `dataExpression` - Should the `data` key be treated as a callback. Useful for supplying `$options['data']` as
     *    another Javascript expression.
     *
     * @param string|array $url Array or String URL to target with the request.
     * @param array $options Array of options. See above for cross library supported options
     * @return string XHR request.
     */
    abstract public function request($url, $options = array());

    /**
     * Create a draggable element. Works on the currently selected element.
     * Additional options may be supported by the library implementation.
     *
     * ### Options
     *
     * - `handle` - selector to the handle element.
     * - `snapGrid` - The pixel grid that movement snaps to, an array(x, y)
     * - `container` - The element that acts as a bounding box for the draggable element.
     *
     * ### Event Options
     *
     * - `start` - Event fired when the drag starts
     * - `drag` - Event fired on every step of the drag
     * - `stop` - Event fired when dragging stops (mouse release)
     *
     * @param array $options Options array see above.
     * @return string Completed drag script
     */
    abstract public function drag($options = array());

    /**
     * Create a droppable element. Allows for draggable elements to be dropped on it.
     * Additional options may be supported by the library implementation.
     *
     * ### Options
     *
     * - `accept` - Selector for elements this droppable will accept.
     * - `hoverclass` - Class to add to droppable when a draggable is over.
     *
     * ### Event Options
     *
     * - `drop` - Event fired when an element is dropped into the drop zone.
     * - `hover` - Event fired when a drag enters a drop zone.
     * - `leave` - Event fired when a drag is removed from a drop zone without being dropped.
     *
     * @param array $options Array of options for the drop. See above.
     * @return string Completed drop script
     */
    abstract public function drop($options = array());

    /**
     * Create a sortable element.
     * Additional options may be supported by the library implementation.
     *
     * ### Options
     *
     * - `containment` - Container for move action
     * - `handle` - Selector to handle element. Only this element will start sort action.
     * - `revert` - Whether or not to use an effect to move sortable into final position.
     * - `opacity` - Opacity of the placeholder
     * - `distance` - Distance a sortable must be dragged before sorting starts.
     *
     * ### Event Options
     *
     * - `start` - Event fired when sorting starts
     * - `sort` - Event fired during sorting
     * - `complete` - Event fired when sorting completes.
     *
     * @param array $options Array of options for the sortable. See above.
     * @return string Completed sortable script.
     */
    abstract public function sortable($options = array());

    /**
     * Create a slider UI widget. Comprised of a track and knob.
     * Additional options may be supported by the library implementation.
     *
     * ### Options
     *
     * - `handle` - The id of the element used in sliding.
     * - `direction` - The direction of the slider either 'vertical' or 'horizontal'
     * - `min` - The min value for the slider.
     * - `max` - The max value for the slider.
     * - `step` - The number of steps or ticks the slider will have.
     * - `value` - The initial offset of the slider.
     *
     * ### Events
     *
     * - `change` - Fired when the slider's value is updated
     * - `complete` - Fired when the user stops sliding the handle
     *
     * @param array $options Array of options for the slider. See above.
     * @return string Completed slider script
     */
    abstract public function slider($options = array());

    /**
     * Serialize the form attached to $selector.
     * Pass `true` for $isForm if the current selection is a form element.
     * Converts the form or the form element attached to the current selection into a string/json object
     * (depending on the library implementation) for use with XHR operations.
     *
     * ### Options
     *
     * - `isForm` - is the current selection a form, or an input? (defaults to false)
     * - `inline` - is the rendered statement going to be used inside another JS statement? (defaults to false)
     *
     * @param array $options options for serialization generation.
     * @return string completed form serialization script
     */
    abstract public function serializeForm($options = array());

    /**
     * Parse an options assoc array into an Javascript object literal.
     * Similar to object() but treats any non-integer value as a string,
     * does not include `{ }`
     *
     * @param array $options Options to be converted
     * @param array $safeKeys Keys that should not be escaped.
     * @return string Parsed JSON options without enclosing { }.
     */
    protected function _parseOptions($options, $safeKeys = array())
    {
        $out = array();
        $safeKeys = array_flip($safeKeys);
        foreach ($options as $key => $value) {
            if (!is_int($value) && !isset($safeKeys[$key])) {
                $value = $this->value($value);
            }
            $out[] = $key . ':' . $value;
        }
        sort($out);
        return implode(', ', $out);
    }

    /**
     * Maps Abstract options to engine specific option names.
     * If attributes are missing from the map, they are not changed.
     *
     * @param string $method Name of method whose options are being worked with.
     * @param array $options Array of options to map.
     * @return array Array of mapped options.
     */
    protected function _mapOptions($method, $options)
    {
        if (!isset($this->_optionMap[$method])) {
            return $options;
        }
        foreach ($this->_optionMap[$method] as $abstract => $concrete) {
            if (isset($options[$abstract])) {
                $options[$concrete] = $options[$abstract];
                unset($options[$abstract]);
            }
        }
        return $options;
    }

    /**
     * Prepare callbacks and wrap them with function ([args]) { } as defined in
     * _callbackArgs array.
     *
     * @param string $method Name of the method you are preparing callbacks for.
     * @param array $options Array of options being parsed
     * @param array $callbacks Additional Keys that contain callbacks
     * @return array Array of options with callbacks added.
     */
    protected function _prepareCallbacks($method, $options, $callbacks = array())
    {
        $wrapCallbacks = true;
        if (isset($options['wrapCallbacks'])) {
            $wrapCallbacks = $options['wrapCallbacks'];
        }
        unset($options['wrapCallbacks']);
        if (!$wrapCallbacks) {
            return $options;
        }
        $callbackOptions = array();
        if (isset($this->_callbackArguments[$method])) {
            $callbackOptions = $this->_callbackArguments[$method];
        }
        $callbacks = array_unique(array_merge(array_keys($callbackOptions), (array)$callbacks));

        foreach ($callbacks as $callback) {
            if (empty($options[$callback])) {
                continue;
            }
            $args = null;
            if (!empty($callbackOptions[$callback])) {
                $args = $callbackOptions[$callback];
            }
            $options[$callback] = 'function (' . $args . ') {' . $options[$callback] . '}';
        }
        return $options;
    }

    /**
     * Convenience wrapper method for all common option processing steps.
     * Runs _mapOptions, _prepareCallbacks, and _parseOptions in order.
     *
     * @param string $method Name of method processing options for.
     * @param array $options Array of options to process.
     * @return string Parsed options string.
     */
    protected function _processOptions($method, $options)
    {
        $options = $this->_mapOptions($method, $options);
        $options = $this->_prepareCallbacks($method, $options);
        $options = $this->_parseOptions($options, array_keys($this->_callbackArguments[$method]));
        return $options;
    }

    /**
     * Convert an array of data into a query string
     *
     * @param array $parameters Array of parameters to convert to a query string
     * @return string Querystring fragment
     */
    protected function _toQuerystring($parameters)
    {
        $out = '';
        $keys = array_keys($parameters);
        $count = count($parameters);
        for ($i = 0; $i < $count; $i++) {
            $out .= $keys[$i] . '=' . $parameters[$keys[$i]];
            if ($i < $count - 1) {
                $out .= '&';
            }
        }
        return $out;
    }

}
